My invention relates to a process for making high purity p-xylene and, more particularly, for making p-xylene with a purity of at least 99.5 %.
In the German Open Patent Application No. 37 03 646 a process for obtaining p-xylene with at least 99.5 % purity from a crude or initial product is described. In this process the crude product is fed in the fluid state to an inert fluid, advantageously water, whose temperature is under the melting point of pure p-xylene. The crystalline material precipitated by agitation is separated in a separator from the inert fluid and subsequently melted. Residual fluid still present in the melting device is separated from the melted crystals and after that is recovered as p-xylene with the desired purity.
With the help of this process using a crude or initial product made in a production plant already existing a p-xylene with a purity of at least 99.5 % can be produced without the present plant being reconstructed and without stopping its operation.